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- #include <u.h>
- #include <libc.h>
- #include <bio.h>
- long
- Bread(Biobufhdr *bp, void *ap, long count)
- {
- long c;
- uchar *p;
- int i, n, ic;
- p = ap;
- c = count;
- ic = bp->icount;
- while(c > 0) {
- n = -ic;
- if(n > c)
- n = c;
- if(n == 0) {
- if(bp->state != Bractive)
- break;
- i = read(bp->fid, bp->bbuf, bp->bsize);
- if(i <= 0) {
- bp->state = Bracteof;
- if(i < 0)
- bp->state = Binactive;
- break;
- }
- bp->gbuf = bp->bbuf;
- bp->offset += i;
- if(i < bp->bsize) {
- memmove(bp->ebuf-i, bp->bbuf, i);
- bp->gbuf = bp->ebuf-i;
- }
- ic = -i;
- continue;
- }
- memmove(p, bp->ebuf+ic, n);
- c -= n;
- ic += n;
- p += n;
- }
- bp->icount = ic;
- if(count == c && bp->state == Binactive)
- return -1;
- return count-c;
- }
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